NEDD9 promotes invasion and migration of colorectal cancer cell line HCT116 via JNK/EMT

Role of Oxidative Stress-Dependent C/EBPβ Expression on CAF Transformation Inducing HCT116 Colorectal Cancer Cell Progression; Migration and Invasion

OBJECTIVE

To investigate oxidative stress-related CAF transformation through C/EBPβ, which affects CRC progression and may have a potential implication for CRC treatment.

METHODS

The conditioned media (CM) from HCT116, CRC cells, was used to activate CCD-18Co, colon fibroblasts, then the ability of activated FBs to induce HCT116 growth and progression was assessed using MTT assay, transwell migration, and matrix invasion assay. Alteration of the cytokine profile and oxidative stress of the activated FBs were studied with cytokine arrays and DCFH-DA assay, respectively. The protein expressions of the CAF markers (α-SMA and FAP) and C/EBPβ were investigated with immunofluorescence and western blotting.

RESULT

It was found that CM from HCT116 cells induced oxidative stress, change of cytokine profile, CAF markers, and the C/EBPβ expression of activated FBs. Furthermore, when the oxidative stress of the activated FBs was suppressed, FAP and C/EBPβ expression were downregulated, correlating with the disabling of their capability to support the cancer progression. The C/EBPβ and prognosis for CRC patients were accessed using the GEPIA dataset, in which high C/EBPβ expression was associated with a poor prognosis.

CONCLUSION

These findings suggest that C/EBPβ expression has a role in CAF transformation in an oxidative stress-related manner and might be used as a target to improve aggressive CRC treatment outcomes.

ANP32A Knockdown Attenuates the Malignant Biological Behavior of Colorectal Cancer Cells by Suppressing Epithelial-mesenchymal Transition and ERK Activation

Acidic leucine rich nuclear phosphoprotein-32A (ANP32A) protein has a variety of functions, such as regulating cell differentiation, influencing cell apoptosis and cell cycle progression. Our previous study demonstrated that high expression of ANP32A was found in the tumor tissues of colorectal cancer (CRC) patients and was positively associated with tumor grading. However, the function and underlying mechanisms of ANP32A in CRC metastasis have not been fully explored. In this study, we found that ANP32A knockdown significantly attenuated the migration and invasion, and epithelial-mesenchymal transition (EMT) in cells. Further mechanistic studies revealed that ANP32A knockdown inhibited the expression of β-catenin and phosphorylated-ERK. The immunofluorescent staining experiment has revealed that ANP32A was expressed in the cell membrane, cytosol and nucleus, and its expression was positively associated with β-catenin expression levels. Moreover, the ability of cell migration and invasion was inhibited, the expression of E-cadherin was enhanced following ANP32A knockdown, and these affects were abolished by an ERK activator PMA, enhanced by an ERK inhibitor PD98059. Moreover, our animal experiment also demonstrated that silenced ANP32A inhibited CRC cell growth, multi-organ metastasis, ERK activation and EMT progression in vivo. Collectively, these findings demonstrated that ANP32A promotes CRC progression and that may be a promising target for the anti-metastasis treatment of CRC.

Loss of MEG3 and upregulation of miR-145 play an important role in the invasion and migration of Cr(VI)-transformed cells

Chronic exposure of human bronchial epithelial BEAS-2B cells to hexavalent chromium (Cr(VI)) causes malignant cell transformation. These transformed cells exhibit increases in migration and invasion. Neuronal precursor of developmentally downregulated protein 9 (NEDD9) is upregulated in Cr(VI)-transformed cells compared to that of passage-matched normal BEAS-2B cells. Knockdown of NEDD9 by its shRNA reduced invasion and migration of Cr(VI)-transformed cells. Maternally expressed gene 3 (MEG3), a long noncoding RNA, was lost and microRNA 145 (miR-145) was upregulated in Cr(VI)-transformed cells. MEG3 was bound to miR-145 and this binding reduced its activity. Overexpression of MEG3 or inhibition of miR-145 decreased invasion and migration of Cr(VI)-transformed cells. Overexpression of MEG3 was able to decrease miR-145 level and NEDD9 protein level in Cr(VI)-transformed cells. Ectopic expression of MEG3 was also shown to reduce β-catenin activation. Inhibition of miR-145 in Cr(VI)-transformed cells decreased Slug, an important transcription factor that regulates epithelial-to-mesenchymal transition (EMT). Inhibition of miR-145 was found to increase MEG3 in Cr(VI)-transformed cells. Further studies showed that mutation of MEG3 at the binding site for miR-145 did not change NEDD9 and failed to decrease invasion and migration. The present study demonstrated that loss of MEG3 and upregulation of miR-145 elevated NEDD9, resulting in activation of β-catenin and further upregulation of EMT, leading to increased invasion and migration of Cr(VI)-transformed cells.

Impacts of MicroRNAs Induced by the Gut Microbiome on Regulating the Development of Colorectal Cancer

Although a dysfunctional gut microbiome is strongly linked to colorectal cancer (CRC), our knowledge of the mediators between CRC and the microbiome is limited. MicroRNAs (miRNAs) affect critical cellular processes, such as apoptosis, proliferation, and differentiation, and contribute to the regulation of CRC progression. Increasingly, studies found that miRNAs can significantly mediate bidirectional interactions between the host and the microbiome. Notably, miRNA expression is regulated by the gut microbiome, which subsequently affects the host transcriptome, thereby influencing the development of CRC. This study typically focuses on the specific functions of the microbiome in CRC and their effect on CRC-related miRNA production and reviews the role of several bacteria on miRNA, including Fusobacterium nucleatum, Escherichia coli, enterotoxigenic Bacteroides fragilis, and Faecalibacterium prausnitzii. Based on the important roles of miRNAs and the gut microbiome in CRC, strategies for modulating miRNA expression and regulating the gut microbiome composition need to be applied, such as bioactive dietary components and fecal microorganism transplantation.

NKCC1 promotes proliferation, invasion and migration in human gastric cancer cells via activation of the MAPK-JNK/EMT signaling pathway

Aims: This study aimed to explore the function of NKCC1 in the proliferation, migration and invasion of Gastric cancer (GC) cells.

Materials and Methods: GC data extracted from the database was analyzed using molecular bioinformatics. The expression levels of NKCC1 in tissue samples from GC patients and GC cell lines were determined by Western blotting, qRT-PCR, and immunohistochemistry. Immunofluorescence was used to detect protein localization. The GC cell lines were transfected with NKCC1-shRNA or expression plasmid, and in vitro proliferation, invasion and migration were analyzed by the CCK8, wound healing and transwell tests.

Results: The NKCC1 mRNA level was significantly increased in GC tissues than that in normal gastric tissues (P = 0.0195). This phenomenon was further confirmed by the analysis of the TCGA-GTEx database that includes 408 gastric cancer tissues and 211 normal gastric tissues (P < 0.01). Furthermore, the increased level of NKCC1 was significantly correlated with Tumor size (P = 0.039), lymphatic node metastasis (P = 0.035) and tumor stage (P = 0.034). In vitro experiments confirmed that NKCC1 expression was higher in GC cells compared to that in GES-1 cells, and was mainly localized to the cytoplasm and membrane. NKCC1 silencing inhibited GC cell proliferation, invasion, migration and EMT, whereas its overexpression had the opposite effects. Furthermore, NKCC1 overexpression upregulated and activated JNK, and the targeted inhibition of JNK by SP600125 abrogated the pro-metastatic effects of NKCC1.

Conclusions: NKCC1 promotes migration and invasion of GC cells by MAPK-JNK/EMT pathway and can be a potential therapeutic target.

Role of microRNA/Epithelial-to-Mesenchymal Transition Axis in the Metastasis of Bladder Cancer

Bladder cancer (BC) is the 11th most common diagnosed cancer, and a number of factors including environmental and genetic ones participate in BC development. Metastasis of BC cells into neighboring and distant tissues significantly reduces overall survival of patients with this life-threatening disorder. Recently, studies have focused on revealing molecular pathways involved in metastasis of BC cells, and in this review, we focus on microRNAs (miRNAs) and their regulatory effect on epithelial-to-mesenchymal transition (EMT) mechanisms that can regulate metastasis. EMT is a vital process for migration of BC cells, and inhibition of this mechanism restricts invasion of BC cells. MiRNAs are endogenous non-coding RNAs with 19-24 nucleotides capable of regulating different cellular events, and EMT is one of them. In BC cells, miRNAs are able to both induce and/or inhibit EMT. For regulation of EMT, miRNAs affect different molecular pathways such as transforming growth factor-beta (TGF-β), Snail, Slug, ZEB1/2, CD44, NSBP1, which are, discussed in detail this review. Besides, miRNA/EMT axis can also be regulated by upstream mediators such as lncRNAs, circRNAs and targeted by diverse anti-tumor agents. These topics are also discussed here to reveal diverse molecular pathways involved in migration of BC cells and strategies to target them to develop effective therapeutics.

Inhibition on JNK Mimics Silencing of Wnt-11 Mediated Cellular Response in Androgen-Independent Prostate Cancer Cells

Prostate cancer (PCa) is one of the most common cancers among men, and one of the leading causes of cancer death for men. The c-Jun N-terminal kinase (JNK) pathway is required for several cellular functions, such as survival, proliferation, differentiation, and migration. Wnt-11, a member of the Wnt family, has been identified for its upregulation in PCa; however, downstream signalling of Wnt-11 remains to be fully characterized. In this study, we investigated the role of the JNK pathway as a potential downstream factor for Wnt-11 signalling. For this purpose, LNCaP, DU145, and PC-3 PCa cells and normal epithelial PNT1A cells were treated with a specific JNK kinase inhibitor: JNKVIII. Our results showed that JNK inhibition decreased mitochondrial membrane potential and promoted cell death in a cell type-dependent manner. We found that JNK inhibition led to an increase in autophagy and prevented epithelial–mesenchymal transition (EMT) in independently growing androgen cells. JNK inhibition and the silencing of Wnt-11 showed similar responses in DU145 and PC-3 cells and decreased metastasis-related biomarkers, cell migration, and invasion. Overall, our results suggest that JNK signalling plays a significant role in the pathophysiology of PCa by mediating Wnt-11 induced signals. Our data highlights that both the JNK pathway and Wnt-11 could be a useful therapeutic target for the combinatory application of current PCa.

Hypoxia-Induced Epithelial-Mesenchymal Transition in Cancers: HIF-1α and Beyond

Metastasis is the main cause of cancer-related mortality. Although the actual process of metastasis remains largely elusive, epithelial-mesenchymal transition (EMT) has been considered as a major event in metastasis. Besides, hypoxia is common in solid cancers and has been considered as an important factor for adverse treatment outcomes including metastasis. Since EMT and hypoxia potentially share several signaling pathways, many recent studies focused on investigate the issue of hypoxia-induced EMT. Among all potential mediators of hypoxia-induced EMT, hypoxia-inducible factor-1α (HIF-1α) has been studied extensively. Moreover, there are other potential mediators that may also contribute to the process. This review aims to summarize the recent reports on hypoxia-induced EMT by HIF-1α or other potential mediators and provide insights for further investigations on this issue. Ultimately, better understanding of hypoxia-induced EMT may allow us to develop anti-metastatic strategies and improve treatment outcomes.

Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis

The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.